diff --git a/src/startup/memory.rs b/src/startup/memory.rs
index 26922dde..60c7f061 100644
--- a/src/startup/memory.rs
+++ b/src/startup/memory.rs
@@ -74,14 +74,16 @@ impl MemoryEntry {
 }
 
 struct MemoryMap {
-    entries: [MemoryEntry; 512],
+    entries: [MemoryEntry; 1024],
     size: usize,
 }
 
 impl MemoryMap {
     fn register(&mut self, base: usize, size: usize, kind: BootloaderMemoryKind) {
         if self.size >= self.entries.len() {
-            panic!("Early memory map overflow!");
+            #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+            unsafe { core::arch::asm!("out dx, al", in("dx") 0x3F8u16, in("al") b'!', options(nostack, preserves_flags)); }
+            panic!("Early memory map overflow at entry {} (max {})", self.size, self.entries.len());
         }
         let start = if kind == BootloaderMemoryKind::Free {
             align_up(base)
@@ -134,7 +136,7 @@ static MEMORY_MAP: SyncUnsafeCell<MemoryMap> = SyncUnsafeCell::new(MemoryMap {
         start: 0,
         end: 0,
         kind: BootloaderMemoryKind::Null,
-    }; 512],
+    }; 1024],
     size: 0,
 });